magnetic field

[Mike Harrison]

On 6 Feb 2004 10:58:26 -0800, testing_h@yahoo.com (Andre) wrote:

Mike Harrison <mike@whitewing.co.uk> wrote in message news:<nv75209mlfpq1t1r2h2mud8hk1dsp0eeeh@4ax.com>...
On Thu, 05 Feb 2004 11:04:54 -0600, El Meda <gomerem@hotmail.com> wrote:

testing_h@yahoo.com (Andre) wrote:

Hi,
Be aware that there is a good possibility that the TIP122 devices you
buy are counterfeit! I just got a bad batch that were not even 122's,
they were PNP darlingtons with internal resistor and diode.

The suspect devices have markings which are unusually large compared
to a genuine ST part, and come off with acetone. You may see a very
faint set of markings just above the fake ones; it appears that the
original markings have been abraded off. Possibly "R6403"

Also the suspect devices are marked as follows,

7 91
TIP122

A "real" device has the markings embossed whereas these appear
"blurred" as you would expect if they had been screen printed.

The other giveaway is that the top corners are straight whereas on a
genuine device these corners are chamfered.


-A

Thanks for the warning. I've found several counterfeit parts myself,
they can be seen at:

http://transfal.tripod.com/

The page is written in spanish, but it has lots of pictures.

---
Ing. Remberto Gomez-Meda <gomerem@hotmail.com
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

It amazes me that someone would bother doing this with such a cheap part...

Well, its not that cheap, the genuine devices are about 60p each. Plus
they seem to be used a lot in a number of consumer products such as
plasma lamps, also some fluorescent lanterns to name a few.

www.findchips.com shows several sources somewhat cheaper, including SGS-Thomson from Future at 20
cents in volume.

 

[Watson A.Name - \"Watt Su]

"Mike Harrison" <mike@whitewing.co.uk> wrote in message
news:nv75209mlfpq1t1r2h2mud8hk1dsp0eeeh@4ax.com...

On Thu, 05 Feb 2004 11:04:54 -0600, El Meda <gomerem@hotmail.com
wrote:

[snip]

It amazes me that someone would bother doing this with such a cheap
part...

Why would you say such a thing? When a distributor sells tape reels of
thousands of these for several thousand dollars, there is _big_money_ to
be made. Very big money.

 

[Mike Harrison]

On Sun, 8 Feb 2004 03:42:54 -0800, "Watson A.Name - \"Watt Sun, the Dark Remover\""
<NOSPAM@dslextreme.com> wrote:

"Mike Harrison" <mike@whitewing.co.uk> wrote in message
news:nv75209mlfpq1t1r2h2mud8hk1dsp0eeeh@4ax.com...
On Thu, 05 Feb 2004 11:04:54 -0600, El Meda <gomerem@hotmail.com
wrote:

[snip]

It amazes me that someone would bother doing this with such a cheap
part...

Why would you say such a thing? When a distributor sells tape reels of
thousands of these for several thousand dollars, there is _big_money_ to
be made. Very big money.

...but surely there must be more expensive parts that would be worth faking - how much margin can
there be in a 20 cent part ?

 

[CWatters]

"Mike Harrison" <mike@whitewing.co.uk> wrote in message
news:3g9c20lt1ejj3lht11s2sun5kha5t1p3l8@4ax.com...

..but surely there must be more expensive parts that would be worth
faking - how much margin can
there be in a 20 cent part ?

But it's not a single 20 cent part. They will be faking expensive reels of
parts.

 

[Watson A.Name - \"Watt Su]

"Mike Harrison" <mike@whitewing.co.uk> wrote in message
news:3g9c20lt1ejj3lht11s2sun5kha5t1p3l8@4ax.com...

On Sun, 8 Feb 2004 03:42:54 -0800, "Watson A.Name - \"Watt Sun, the
Dark Remover\""
NOSPAM@dslextreme.com> wrote:


"Mike Harrison" <mike@whitewing.co.uk> wrote in message
news:nv75209mlfpq1t1r2h2mud8hk1dsp0eeeh@4ax.com...
On Thu, 05 Feb 2004 11:04:54 -0600, El Meda <gomerem@hotmail.com
wrote:

[snip]

It amazes me that someone would bother doing this with such a cheap
part...

Why would you say such a thing? When a distributor sells tape reels
of
thousands of these for several thousand dollars, there is _big_money_
to
be made. Very big money.

..but surely there must be more expensive parts that would be worth
faking - how much margin can
there be in a 20 cent part ?

It's not how many cents, it's how many _percent_. If the distrib buys a
couple hundred thousand parts at 5 cents and sells them for 25 cents,
that's a decent year's wage for someone! Forty thousand dollars!

 

[Frank Bemelman]

"Tom Del Rosso" <tdnews01@att.net.invalid> schreef in bericht
news:yuQVb.205453$6y6.4145060@bgtnsc05-news.ops.worldnet.att.net...

In news:mlif209bci7rdaka0o8c21s121j1t8tpqb@4ax.com,
Jim Thompson typed:

It always warms the cockles of my heart when I see so many different
model parameters for the same device :-(

But it might be less than the diversity in actual parts.

Ah, there's the bright side ;-)

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

 

[Zak]

Mike Harrison wrote:

..but surely there must be more expensive parts that would be worth faking - how much margin can
there be in a 20 cent part ?

Well.. they probably want the parts to work a bit, so they work when
under light test, or in the majority of applications.

This is probably harder for more complex or more critical components.


Thoms

 

[Michael A. Terrell]

Jim Thompson wrote:

I think a once an hour reset would be more than adequate, in fact I'm
thinking once-in-24-hours would be just ducky. 32KHz resonators
aren't *that* bad.

Think outside the box!

You can access the WWVB atomic clock online, so build a 60 KHz
transmitter and use the NIST modulation system to let you use standard
"Atomic wall clocks" anywhere you want around your house, or property.
It would be easier to build the transmitter than the custom clocks. Then
you can have as many displays as you need, with very little extra cost.
You can buy a cheap 60 KHz crystal for the transmitter, or use a higher
frequency crystal and divide it down.

Modulation is simple: a 10 dB reduction in level, at a one bit ber
second data rate.

If you want to be more creative, build a 60 KHz repeater. ;-)

--
We now return you to our normally scheduled programming.

Michael A. Terrell
Central Florida

 

[Jim Thompson]

On Fri, 13 Feb 2004 15:09:08 GMT, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Jim Thompson wrote:


I think a once an hour reset would be more than adequate, in fact I'm
thinking once-in-24-hours would be just ducky. 32KHz resonators
aren't *that* bad.

Think outside the box!

You can access the WWVB atomic clock online, so build a 60 KHz
transmitter and use the NIST modulation system to let you use standard
"Atomic wall clocks" anywhere you want around your house, or property.
It would be easier to build the transmitter than the custom clocks. Then
you can have as many displays as you need, with very little extra cost.
You can buy a cheap 60 KHz crystal for the transmitter, or use a higher
frequency crystal and divide it down.

Modulation is simple: a 10 dB reduction in level, at a one bit ber
second data rate.

If you want to be more creative, build a 60 KHz repeater. ;-)

As usual, Michael, you're not paying attention.

I have NIST on my machine, checked every 60 minutes.

WWVB signal is too weak in my rock pile location.

For WWVB signals, see my website, I designed a custom chip *many*
years ago.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Frank Bemelman]

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> schreef in bericht
news:+3WqbOChb1LAFwWk@jmwa.demon.co.uk...

I read in sci.electronics.design that Rich Grise <null@example.net
wrote (in <NdDXb.23114$1S1.7746@nwrddc01.gnilink.net&gt about 'OT! OT!
Not in Arizona', on Sun, 15 Feb 2004:

You know, don't you, that George W. Bush is the reincarnation of Adolf
Hitler?

No he isn't. There is incontrovertible evidence that Adolf is a small
earthworm in the garden of 23 Railway Cuttings, Cheam, England. (;-)

GWB may be the reincarnation of someone/something else. But he doesn't
come across as evil to me. Misguided and ill-informed, but not evil.

What a relief. We can all go to bed now and have sweet dreams.

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

 

[John Woodgate]

I read in sci.electronics.design that Frank Bemelman
<fbemelx@euronet.invalid.nl> wrote (in <402f5c0e$0$65163$d5255a0c@news.w
anadoo.nl&gt about 'OT! OT! Not in Arizona', on Sun, 15 Feb 2004:

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> schreef in bericht
news:+3WqbOChb1LAFwWk@jmwa.demon.co.uk...
I read in sci.electronics.design that Rich Grise <null@example.net
wrote (in <NdDXb.23114$1S1.7746@nwrddc01.gnilink.net&gt about 'OT! OT!
Not in Arizona', on Sun, 15 Feb 2004:

You know, don't you, that George W. Bush is the reincarnation of Adolf
Hitler?

No he isn't. There is incontrovertible evidence that Adolf is a small
earthworm in the garden of 23 Railway Cuttings, Cheam, England. (;-)

GWB may be the reincarnation of someone/something else. But he doesn't
come across as evil to me. Misguided and ill-informed, but not evil.

What a relief. We can all go to bed now and have sweet dreams.

Misguided and ill-informed people can be quite as dangerous as evil
ones, but they don't mean it.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Michael A. Terrell]

Jim Thompson wrote:

On Fri, 13 Feb 2004 15:09:08 GMT, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

Think outside the box!

You can access the WWVB atomic clock online, so build a 60 KHz
transmitter and use the NIST modulation system to let you use standard
"Atomic wall clocks" anywhere you want around your house, or property.
It would be easier to build the transmitter than the custom clocks. Then
you can have as many displays as you need, with very little extra cost.
You can buy a cheap 60 KHz crystal for the transmitter, or use a higher
frequency crystal and divide it down.

Modulation is simple: a 10 dB reduction in level, at a one bit ber
second data rate.

If you want to be more creative, build a 60 KHz repeater. ;-)

As usual, Michael, you're not paying attention.

You either didn't read, or understand my post.

I have NIST on my machine, checked every 60 minutes.

I noted that in my message.

WWVB signal is too weak in my rock pile location.

Also noted

For WWVB signals, see my website, I designed a custom chip *many*
years ago.

You have said this, many times.

You also ignored the part about building a transmitter to drive the
standard radio controlled clocks, and driving it with the time data from
your PC that is updated from the atomic clock in Bolder. Co. the
transmitter woulkd be very simple. A crystal, a analog switch to shunt
the signal across a resistor to control signal level, and a single gain
stage to drive a loopstick anteanna.

Digikey has a 60 KHz crystal for the transmitter. As you know, he
time code is a simple one bit per second format. The 10 dB signal level
reduction used to modulate the carrier is quite simple, as well. That
leaves a microprocessor of your choice to receive the data from the PC
on any port of your choice. Then it reformats the time code and
modulates the 60 KHz carrier. Personally, I would use something like the
Rabbit Semiconductor development board with a ethernet interface. Then
it can be placed anywhere on your home network that is convenient to
transmit to all the radio controlled clocks.


http://www.digikey.com/
Digikey part number: SE3320-ND, Epson Electronics America, Inc. part
number: C-2 60.0000K-P crystal, price $1.23000 each, 4439 in stock


http://www.rabbitsemiconductor.com/products/kits/index.shtml


--
We now return you to our normally scheduled programming.

Michael A. Terrell
Central Florida

 

[Jim Thompson]

On Sun, 15 Feb 2004 18:01:17 GMT, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Jim Thompson wrote:

On Fri, 13 Feb 2004 15:09:08 GMT, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

Think outside the box!

You can access the WWVB atomic clock online, so build a 60 KHz
transmitter and use the NIST modulation system to let you use standard
"Atomic wall clocks" anywhere you want around your house, or property.
It would be easier to build the transmitter than the custom clocks. Then
you can have as many displays as you need, with very little extra cost.
You can buy a cheap 60 KHz crystal for the transmitter, or use a higher
frequency crystal and divide it down.

Modulation is simple: a 10 dB reduction in level, at a one bit ber
second data rate.

If you want to be more creative, build a 60 KHz repeater. ;-)

As usual, Michael, you're not paying attention.

You either didn't read, or understand my post.

I have NIST on my machine, checked every 60 minutes.

I noted that in my message.

WWVB signal is too weak in my rock pile location.

Also noted

For WWVB signals, see my website, I designed a custom chip *many*
years ago.

You have said this, many times.

You also ignored the part about building a transmitter to drive the
standard radio controlled clocks, and driving it with the time data from
your PC that is updated from the atomic clock in Bolder. Co. the
transmitter woulkd be very simple. A crystal, a analog switch to shunt
the signal across a resistor to control signal level, and a single gain
stage to drive a loopstick anteanna.

Digikey has a 60 KHz crystal for the transmitter. As you know, he
time code is a simple one bit per second format. The 10 dB signal level
reduction used to modulate the carrier is quite simple, as well. That
leaves a microprocessor of your choice to receive the data from the PC
on any port of your choice. Then it reformats the time code and
modulates the 60 KHz carrier. Personally, I would use something like the
Rabbit Semiconductor development board with a ethernet interface. Then
it can be placed anywhere on your home network that is convenient to
transmit to all the radio controlled clocks.


http://www.digikey.com/
Digikey part number: SE3320-ND, Epson Electronics America, Inc. part
number: C-2 60.0000K-P crystal, price $1.23000 each, 4439 in stock


http://www.rabbitsemiconductor.com/products/kits/index.shtml

The real trick is outputting on the serial port in a timely ;-)
fashion.

The link is the least of the issues.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Richard Crowley]

"Michael A. Terrell" wrote ...

You also ignored the part about building a transmitter to drive the
standard radio controlled clocks, and driving it with the time data from
your PC that is updated from the atomic clock in Bolder. Co. the
transmitter woulkd be very simple.

Imagine the fun you could have by setting up your own
competition to WWVB in your neighborhood! Almost
certainly illegal, but the FCC is pretty toothless these
days anyway.

</sarcasm>
<serious>

Actually not a bad idea, but make sure your signal can't
be detected at your property line!

Another consideration. If there is any "leakage" of the REAL
WWVB signal into your area, you might have a tough time
differentiating between 10db, 1Hz "AM" and beat artifacts
between you and the real thing.

 

[Michael A. Terrell]

Richard Crowley wrote:

"Michael A. Terrell" wrote ...
You also ignored the part about building a transmitter to drive the
standard radio controlled clocks, and driving it with the time data from
your PC that is updated from the atomic clock in Bolder. Co. the
transmitter woulkd be very simple.

Imagine the fun you could have by setting up your own
competition to WWVB in your neighborhood! Almost
certainly illegal, but the FCC is pretty toothless these
days anyway.

/sarcasm

They only react to complaints, and spend the rest of their time
making their required visits to commercial radio and TV stations.

serious

Actually not a bad idea, but make sure your signal can't
be detected at your property line!

Another consideration. If there is any "leakage" of the REAL
WWVB signal into your area, you might have a tough time
differentiating between 10db, 1Hz "AM" and beat artifacts
between you and the real thing.

Jim said he was down in a hole with no signal at all so he should
have that problem. If anyone else picked up his signal, they wouldn't
know the difference. I don't need a transmitter here in Ocala. The WWVB
signal comes in well, and shows full strength on my clock's signal level
indicator. I'm about as far as you can get from the transmitter, without
moving to Miami.

--
We now return you to our normally scheduled programming.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

Jim Thompson wrote:

The real trick is outputting on the serial port in a timely ;-)
fashion.

The link is the least of the issues.

That is why I would use the Ethernet port and set the transmitter's
processor at night, during lunch, or any time your network won't be busy
enough to delay the data packets. Then you can measure the number of
seconds it takes to transmit the full data, (it should be one minute)
then add that to the microprocessor's software. You should be able to
set the clocks to a fraction of a second, with a little bit tweaking.


--
We now return you to our normally scheduled programming.

Michael A. Terrell
Central Florida

 

[John Larkin]

On Sun, 15 Feb 2004 13:12:26 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

You know, don't you, that George W. Bush is the reincarnation of Adolf
Hitler?

No he isn't. There is incontrovertible evidence that Adolf is a small
earthworm in the garden of 23 Railway Cuttings, Cheam, England. (;-)

GWB may be the reincarnation of someone/something else. But he doesn't
come across as evil to me. Misguided and ill-informed, but not evil.

What a relief. We can all go to bed now and have sweet dreams.

Misguided and ill-informed people can be quite as dangerous as evil
ones, but they don't mean it.

Are you suggesting that GWB might be 'quite as dangerous' as Hitler?
That's sad.

John

 

[John Woodgate]

I read in sci.electronics.design that John Larkin <jjlarkin@highSNIPland
THIStechPLEASEnology.com> wrote (in <a2g230d9a8mk289uvleat8hiv814b5sbp7@
4ax.com&gt about 'OT! OT! Not in Arizona', on Mon, 16 Feb 2004:

Are you suggesting that GWB might be 'quite as dangerous' as Hitler?
That's sad.

Yes, he *might* be, if everything went the wrong way. Suppose something
he did unintentionally provoked a war with China. That would be pretty
dangerous. But he *probably* won't be.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[John Larkin]

On Mon, 16 Feb 2004 23:33:25 +0000, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that John Larkin <jjlarkin@highSNIPland
THIStechPLEASEnology.com> wrote (in <a2g230d9a8mk289uvleat8hiv814b5sbp7@
4ax.com&gt about 'OT! OT! Not in Arizona', on Mon, 16 Feb 2004:

Are you suggesting that GWB might be 'quite as dangerous' as Hitler?
That's sad.

Yes, he *might* be, if everything went the wrong way. Suppose something
he did unintentionally provoked a war with China. That would be pretty
dangerous. But he *probably* won't be.

Well, that's just chaos theory. I could drop a banana peel on a
sidewalk somewhere and wind up destroying France.

Not by intent, of course.

John

 

[Jim Thompson]

On Mon, 16 Feb 2004 16:48:41 -0800, John Larkin
<jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote:

[snip]

Well, that's just chaos theory. I could drop a banana peel on a
sidewalk somewhere and wind up destroying France.

Not by intent, of course.

John

But enjoy it, just the same ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.